Oil vaporizing apparatus



July 5, 1938. c. A. FRENCH OIL VAPOHIZINC'y A.PARATUS Filed Dec.

.ll/Illlllfllllllllflf Patented July 5, 1938 UNITED STATES 2,122,685 on. vAPoRIzlNG APPARATUS Charles A. French, Riverside, Ill., assignor to Mark C. Bates, Chicago, Ill.

Application December 12, 1936, Serial No. 115,496

10 Claims.

My invention relates to the vaporization of liquids, particularly relatively heavy liquid hydrocarbons and similar substances. l

In my prior application, Serial No. 47,910, led

5 November 1, 1935, I disclosed a method of vaporizing relatively heavy liquid hydrocarbons wherein an excess of fuel oil is maintained in a vaporization chamber and hot inert products of combustion are brought into contact with said fuel oil and a portion of the fuel oil vaporized by contact with said hot products of combustion.

In my prior application I disclosed the utilization of a pool of oil through which the hot products of combustion were caused to pass, and also the utilization of a spray which at all times projected into the path of the hot products of combustion a greater amount of liquid fuel than could be vaporized during the maximum demands placed upon the apparatus in which the method was embodied.

The principal object of my present invention is to utilize in the method disclosed in my previous application a modified means for presenting into the path of the hot products of combustion the excess of liquid fuel utilized in accordance with my basic method.

Another object is to improve the method described in my prior application. Still another object is to provide simplified and efficient apparatus for carrying out said method.

In accordance with my present invention I provide in a vaporizing chamber an excess of liquid to be vaporized, this excess of liquid being caused to flow down a surface presented in the path of hot inert products of combustion in such a manner that such surface is at all times completely wetted with the liquid. In this manner vaporization takes place from the surface of the liquid which at all times is at a relatively elevated temperature but substantially below the boiling point of the liquid, the liquid vapors being entrained in the hot products of combustion or other hot products substantially inert to the liquid being vaporized. According to my method the hot o products of combustion retain the vapor and condensation is avoided in somewhat the same manner that dry air will pick up moisture and retain the same as long as the so-called dew point is not exceeded.

Other objects and features of my invention will be apparent from a consideration of the following detailed description taken with the accompanying drawing wherein Fig. 1 is a vertical sectional view of apparatus embodying the features of my invention and with which my modified and improved method may be practiced, and

Fig. 2 shows a modified form utilizing the same general features as those illustrated in Figure l.

For convenience in describing my invention I shall first refer to Figure l showing one embodiment of apparatus for carrying out my improved method and thereafter point out in further detail features and advantages in connection therewith.

In Fig. l I show a vaporization chamber lll adapted to contain a supply of oil l l maintained at a constant level by' level control device l2, fresh oil being supplied to the pool thereof in the vaporizatiorl chamber from a pipe i3, a pipe Hl connected to the level control device being connected to a fresh oil tank not shown. A pressure equalizing line l5 is provided between the oil control device 12 and the vaporization chamber.

The vaporization chamber I0 has an upper extension I6 through which vapors are adapted to be drawn, this upper extension terminating in a relatively narrow throat Il connected to a .Venturi tube I3. A butterfly type of valve I9 is provided in the throat Il to facilitate control of vapors. Air is delivered to the Venturi tube 25 through a forcing nozzle 2l, a pipe 22 connected to the forcing nozzle being connected to a source of air under pressure, for example, a conventional type of positive pressure blower.

Venturi tube I8 is connected to manifold 23 which manifold is adapted to deliver a combustible mixture to suitable combustion devices, for example, burners.

In the path of the combustible mixture delivered to the manifold 23 I provide a robber tube 3- 24 for withdrawing combustible mixture and delivering the same to a pilot burner 26. The combustible mixture so delivered is burned at the pilot burner and the hot products of combustion are delivered to the vaporization chamber where they pass downwardly through a downcomer tube 2l.

In the path of the hot products of combustion, I provide a fountain 28 adapted at all times to be covered with a layer or lm of oil to be vaporzed as will be explained more in detail hereinafter. A pump 29 withdraws hot oil from the bottom of the vaporization chamber through a pipe 3i and delivers the same back to the fountain 28 through pipe 32. The fountain comprises an outer tube indicated as circular in cross section but adapted to have other suitable shapes if desired and an inner tube through which the incoming oil is delivered to the top of the outside tube. The fountain is so contructed that the por- 55 j tion thereof exposed to hot products of combusered with oil with the exception of'an tion passing through.- the downcomer is all covupper tip 33. T his, however, is constructed so as to avoid transmission of heat tothe inside of the fountain in such a way as to produce carbon formation;

In the form shewn a small amount of carbon may form near the lower part of tip 33 unless caution is observed to avoid splashing of the oil into the relatively hot outside surface of the tip. splashing is to a great extent avoided by shaping the annulus of the outside member of the fountain so as to cause an even and smooth iiow. In

the form of device shown, however, this is the only portion which accumulates any carbon under any circumstances even after relatively long periods of operation and such carbon as may accumulate at the upper part of the fountain is readily removed by a simple cleaning operation.

In the form of the device shown in Fig. 2 I also f employva vaporization chamber indicated by the the bottom of the vaporizaticn champ-er and deliver the same to the inside of the fountain 39. In this form of device no head or tip is provided on the fountain, smoothness of ilow being obtained4 due to the relatively larger body of oil moved along the fountain and also due in part to the fact that the speed with which the oil moves upwardly is decreased as the wider inside portion at the top is reached.

Vaporizaticn may occur, therefore, not only along the sides of the fountain but also from the relatively large surface area of oil at the top of the fountain. In this form also, as in Fig. 1, fresh oil is supplied to the pool of oil in the vaporization chamber by -a level control device43.

The vaporzing apparatus shown in Figure 2 is operated 'on the suction principle, a fan 44' being provided with its suction side connected to a mixing chamber 46 and its pressure side connected to a manifold 41.

'I'he vaporization chamber has an upper extension 43 terminating in a throat 49 connected to the'mixing chamb-eij 46. Air is admitted to the mixing chamber through an air intake 5I, the effective area of which may be adjusted manually or auternatically by suitable means.

The manifold 41 receives combustible mixture from the mixing chamber 46 through the oper' ation of the blower 44, which blower is operated by suitable means, not shower. A robber tube 52, similar-to the tube 24' disclosed in Fig. 1, withdraws combustible mixture from the manifold and delivers the same te a pilot burner 53. Hot products of combustion from the pilot burner 53 are delivered te the downcomer in the same manner described in connection with the foregoing em. bodiment.

Besides the difference in tle manner of introducing the air and mixing the same 'with the vaporous mixture withdrawn from the vaporization chamber, Fig. 1 and Fig. 2 also illustrate the modifications in the structure and operation of' the fountain. Each, however, embodies substantially the same general concept and produces submay be practiced in other bon dioxide, water vapor and nitrogen. Other substances are calculated to be present, but if present comprise such a small proportion of the total products of combustion that they are not detectablel by ordinary method of analysis. No free oxygen nor uncombined hydrocarbon material are found, that is to say, the products are neither oxidizing nor reducing. It should be borne in mind, however, that the device can be controlled so that either a reducing or oxidizing name is produced in combustion apparatus, it being desirable, however, whatever adjustments may be employed, that the pilot burner be sc adjusted that substantially a neutral c-r inert 'combustion product will'be produced.

'I'he hot products of combustion pass over the v surface of the fountains and withdraw vapors from the surface ci the oil as it flows down the fountain. This preduces some cooling effect Von the hot preducts of combustion, but should there be any tendency for excessive condensation of vapors, such condensation is prevented by the vaporous mixture passing over the heated surfaces of the downcomer tube in its path to the upper part of the vaporization chamber.

In addition to the fact that the hot gases coming in contact with the oil are substantially inert by reason of the perfect combustion obtained, and the fact that they are allowed to cool to a temperature it-elow the temperature of dissociation,

namely, about 1600 F., other factors have an important bearingupon the eiiiciency and freedem of carbon formation in the present levention. The liquid fuel oil is at times out of contact with metal surfaces having a temperature substantially higher than that of the oilI itself. In other words, the oil is not coming in contact with suilciently hot surfaces so as to cause carbon formation at the point of contact.-

Another feature is that liquid fuel particles do not become entrained in the gas or vapor flow. thus further eliminating the possibility ef the liquid oil being brought into contact with heated surfaces in such a way as to cause carbon or sludge formation. Another feature is that the fuel vapor is quickly remeved from contact with the liquid fuel. Still another characteristic is that eddy currents of fuel vapor in contact with metal surfaces are avoided except in the mixing chamber where considerable turbulence not only is not objectionable but has certain advantages in promoting satisfactory mixing.

In the operation of the apparatus in accordance with either Fig. 1 or 2, hot oil iscontinuously withdrawn from the bottom of the vaporizing chamber and delivered te the fountain, incoming or freshly supplied oil being mixed with the hot oil in the bottom of the vaporization chamber as itis added ther-etc.

'I'hose skilled in the t e method utilized in art will understand that operating the apparatus ways, employing various constructions and various modi'cations while still practicing the same method. Although the method is in general understandable by reference to the apparatus, and the functioning thereof, those skilled in the art may have a better understanding of the invention by more complete reference to the methoditself. y

The main steps and features of the device are utilized by passing liquid, relatively heavy, hydrocarbon, preferably in the form of a relatively thin film, wherebyto control the flow, over a relatively cool surface. This cool surface is entirely covered with the liquid hydrocarbon so that hot products of combustion do not strike any metal surface free of oil but wetted or contacted with oil. As an illustration, should the fountains be so modified that only a portion of the surface was covered with oil, then -carbon would form at the boundary line between the surface covered with oil and the surface not covered with oil. It will be noted that in no case in the apparatus shown is this condition permitted to exist. The hot inert products of substantially complete combustion are then passed over the surface of the liquid hydrocarbon so as to pick up vapors from the surface.

At no time, however, does suilicient evaporation' occur from the surface to leave such surface dry. The surface is at all times completely wetted with the oil. Y

According to'the preferred manner of practiclng the method, the vapors are combined with air and. burned. At least a portion of the resulting hot .gases of combustion burned in either a main burner or a pilot burner are then utilized for vaporization purposes. It is obvious, however, that I may employ any hot, substantially inert gas, whether generated or heated by the particular piece of apparatus being operated, from a similar piece of apparatus acting as a pilot or from an entirely unrelated and entirely dierent piece of apparatus, depending upon conditions encountered in actual practice.

It has been found that when the vaporizatlon medium is a hot inert gas a relatively very heavy liquid hydrocarbon may be vaporized and when the hydrocarbon in liquid condition is maintained out of Contact with hot surfaces, cracking, carbonization and the like are prevented. In addition, by means of the present method, relatively large particles of liquid are not entrained in the vaporous products, thus avoiding carbonization by such liquid particles coming in contact with hot surfaces. In the preferred operation of the method, the mixture of inert gases and vapors which may be referred to as vaporous products come in contact with hot surfaces of the downcomer tube and these hot surfaces function as a super-heater. Preferably, some form of superheating device of the character shown or of a modified character is employed.

l By means of my method, relatively heavy liquid hydrocarbon may be vaporized Without carbon formation, and employing any given piece of apparatus a considerable range is permissible; that is to say, a relatively large amount of vapors may be produced or a relatively very small amount of vapors may be produced without in any way deleteriously affecting the operation; Various features may be employed to initiate vaporization, particularly when the hydrocarbon is relatively very heavy. It may be stated generally that any method which brings the oils up to a relatively high temperature, but not above their boiling point, may be employed. For example, before 715 the oilfis introduced into the apparatus, the vaporization chamber and related parts may be heated with a blowv torch, or the blower may be operated while holding a flame at the pilot burner so`that the hot gases pass down through the downcomer. A suitable method is initially to mix with the relatively heavy hydrocarbons a small quantity of gasoline or other more volatile fuel. On operation of the blower, sulcient of the vola- .tile liquid is vaporized so that the pilot burner may be lighted and operation started at once. As the unit comes up to temperature, the gasoline supply may be gradually reduced and finally entirely cut oif, vaporization being then continued in the regular manner employing only the relatively heavy hydrocarbon. Another simple method of starting is rst to re the pilot burner with commercial gas, and after vaporization has been initiated, substitute for the commercial gas at the pilot burner the vaporous products resulting from the operation of the apparatus. Whatever the method employed, vaporization may be started very quickly. There are several obvious advantages in the practice of my method. One advantage is that the amount of oil delivered for vaporization, for example, to a fountain or surface s which is to be covered with oil, is not critical since more oil is delivered than can be vaporized at any one time, the amount may be increased or decreased considerably from the calculated amount and vaporization continues to take place without difficulty. Obviously theY amount should not be decreased below the point where anexcess will remain even at maximum operation. In addition, the fuel level maintained by the fuel level control system is not critical. For example, the height of the oil in the bottom of the vaporization chamber through faulty operation of the mechanism or through lack of accurate control may be raised or lowered considerably and yet operation will continue to take place. A further advantage and feature is that the liquid oilis at all times prevented from coming into contact with metal surfaces at temperatures substantially higher than the temperature of the liquid oil. The vapors, however, may and do come in contact with hot surfaces with the advantage previously outlined. In other words, the only oil coming in contact with surfaces hotter than the oil itself is in the form of vapor.

I claim:

l. A method of vaporizing a heavy fuel oil which comprises flowing the oil along a relatively cool surface in such manner that all of said surface is at all times wetted with said oil, and passing over the surface of said oil while ilowing, a current of hot, inert gas, whereby to withdraw vapors from the surface of said oil and mix the same with said hot inert. gases, said surface being substantially unheated except for the heat which is conducted thereto by the fuel oil flowing into direct contact therewith.

2. A method of vaporizing a heavy fuel oil which comprises flowing the oil along a relatively cool surface in such manner that all of said surface is at all times wetted with said oil, and passing over the surface of said oil While flowing, a current of hot, inert gas, whereby to withdraw vapors from the .surface of said oil and mix the same with said hot inert gases, and thereafter to impart additional heat to the resulting mixture of vapor and hot gas to inhibit possibility of condensation of said vapors, said surface being substantially unheated except for the heat which is conducted thereto by the fuel oil flowing into direct contact therewith.

,3. A method of vpdrizing a. heavy fu'ei face is at all-times wetted'with said oil, and passing '.1",overthe surface of said oil while owing. a

current of hot,- inert'g'as, whereby to withdraw vapors ffrom the surface of saidjilfand mix the same with saidhot inert gases', and-.thereafter mixing with said gas andvapor a proportion of air Isuillcient to form a combustible mixture, said surface being substantially unheated except for the heat which is 'conducted thereto by the fuel oil owing into direct contact therewith.

4. A method of vaporizing" a heavy fuel oil which comprises owing the oil along a relatively cool surface in such manner that all of said surface is at all times wetted with said oil, and passing over the surface of said oil while flowing,

" a current of hot, inert gas, whereby to withdraw vapors from the surface of said oil and mix the same with said hot inert gases, thereafter mixing with said gas and vapor a proportion of air suflicient to form a combustible mixture, com"- Apietely burninga portion of such combustible mixture to produce gaseous products of combustion, and utilizing hot products of said combustion for vaporizing said fuel oil, s aid surface being substantially unheated except for the heat which is conducted thereto by the fuel oil owing into direct contact therewith. Y I.

5. The method of vaporizing relatively heavy fuel oil which comprisesmaintaining a pool of said oil in a relatively cool vaporization chamber, continuously supplying oil fromv the vaporization .chamber to the top of a fountain in sufficient amount so as. entirely to cover the exterior surface of the fountain and permit an excess to'fiow back to the said body of oil, and continuously passing hot substantially inert gases downwardly over` the surface of the oil on said fountain and in said body of oil, said surface being substantially unheated except'for the heat which is conducted thereto by the fuel oil flowing into direct contact therewith. y

6. The method of vapcrizing relatively heavy fuel oil which comprises maintaining a pool of said oil in a relatively cool vaporization chamber, continuously supplying oil from the vaporization chamber to the top of a fountain in sufficient amountso as entirely to cover the exterior surface of the fountain and permitan excess to flow back to the said body of oil, and continuous ly passing hotsubstantially inert gases over the surface of the oil on said fountain 'andcin said body of oil, the inert gases being'products of combustion formed by substantially completely burning a portion o f the fuel cil vapors, said surface being substantially unheated except for the heat which is conducted thereto by the fuel oil flowing into direct contacttherewith.

l oil which 'comprises iiowing the oil along arelatively cool surface in such manner that all o'f said sur- 7. Ihe method of vaporizing a-relatively heavy fuel oil which comprises withdrawing vapors from a vaporization chamber, mixing said vapors with air sufllcie'nt for-complete combustion, burning a portion of said mixture, flowing oil to be vaporized downwardly around a relatively cool surface in the vaporization chamber in asumcient amount to maintain a coating ofoil at all times on all portions of said surface, and

passing the products resulting from the combustion of a portion of .said mixture into the vaporfization chamber into contact with the surface of the oil, said surface being substantially unheated except for the heat which is conducted thereto by the fuel oil owing into direct contact therewith.

'8. In an oil vaporizer, a vaporization chamber, anexterior surface therein, means for flowing -oi1 downwardly on said. surface in sufficient quantity whereby said surface is at all times covered with oil, means for withdrawing vapors from 'the upper part .of the vaporization chamber, means for mixing said vapors with air suillcient for complete combustion. means for burning at least a portion of such mixture, and means for delivering hot inert products of combustion resultlng from burning at least a portion of said mixture to the vaporization chamber into contact with the oil on said surface.

-il. Inan oil vaporizer, afountain, means for delivering oil to the top of said fountain and al- L lowing the same to flow down the outside thereof whereby the entire outside surface of said fountain is at all times covered with oil, a pilot burner, .means for moving hot products of combustion from said pilot burner along the surface of said oil on said fountain, whereby to withdraw vapors from the surface of said oii and mix the same with the hot products of combustion to form a vaporous mixture and means for mixing said vaporous mixture with air to produce a com- 4 bustible mixture and means for withdrawing a portion of said combustible mixture and delivering the same to said pilot burner.

10. In an oil vaporizer, a vaporization chamber, means for maintaining an excess of oil in the 4 form of a pool in the vaporization chamber.' a

fountain projecting upwardly from said pool of oil, means for withdrawing oil from said pool and delivering the same to the top of the fountain whereby to cause the oil to ow down the outside 5 thereof, a pilot burner, a passageway leading -from the pilot burner to the fountain whereby to cause hot products of combustion of the pilot burner to come directly into contact with the outside of the fountain whereby to vaporize oil 5 ,from the surface thereof, and means for withdrawing from the vaporization chamber the resulting mixture of combustion products and oil vapor.

CHARLES A. FRENCH. 01 

